Well crap. Is it unsafe to use in my rifle? Or is it just a reliability issue?
Well like I said I haven't used triple 777 in my rifles. (All of which are Traditional style weapons,) so I don't know of any 777 shortcomings that may exist when used in a Traditional application. But according to shortwave he has used it. Perhaps your questions (above) should be directed to shortwave. I'm sure He has the answers your looking for in regards to your situation. (or read the next quote below)
From what I know about 777 chickenmcnasty comes from a few friends who are in-line shooters. Their rifles are ignited with 209 primers. Not #11 caps. Its their
powder of choice. Not mine.
Per shortwave's thread (seen above): Sure Shot,
It's not my fav. powder but I've used 777 in most of my hammer guns and just like Pyrodex, have not had any ignition problems.
Just remember chicken, you must reduce the amount of 777 used by 15% compared to other powders such as Pyrodex. Triple Seven is about 15% 'hotter' then other conventional powders
So with that said. I guess all you have to remember is to drop your volume charge rate 15% when using Triple 777 in a Traditional application. That's not that hard to accomplish is it.